Here are some problems which needs to be fixed which I have experienced:

- Fullcreen. It need to come a fix which enables fullscreen.
- Connection failed. A lot of times, the launcher can't connect.
- I can't download the "Troll Trouble" DLC. It just downloads the 7 MB file over and over again.
- Fix the 3D vision lag problem!!

1.) You mean it runs in window mode? Press Alt + Enter and it should switch to full screen. Or are you talking about the black bars? Yeah, this has to be patched though there is the possibility they will never do it.

2.) Known problem, it seems they still have server problems. I figured that waiting up to 30 seconds lets the launcher log in most of the time.

3.) Search for the DLC in your "Documents\The Witcher 2" folder or - ADVANCED USERS ONLY - for a registry entry concerning the DLC. Erase the content and re-download. If it still doesn't work send a message to the support: help2start@thewitcher.com

4.) You can easily fix this by yourself by uninstalling the 3D vision component of the driver. Until Nvidia fixes the problem with a new driver version this is your only option and it is reported working.